robin redbreast vs robin

robin redbreast and robin both are nouns.

Word	Noun	Adjective	Verb	Adverb
robin redbreast	Yes	No	No	No
robin	Yes	No	No	No

As nouns, robin redbreast and robin are synonyms defined as:

robin redbreast and robin: small Old World songbird with a reddish breast

Other synonyms of robin redbreast include Erithacus rubecola, Old World robin, redbreast.

robin redbreast (noun)	robin (noun)
small Old World songbird with a reddish breast	large American thrush having a rust-red breast and abdomen
	small Old World songbird with a reddish breast